1. The Field of the Invention
The present invention relates generally to thermoplastic films. Specifically, the invention relates to multi-ply thermoplastic films with increased loft and to methods of manufacturing thermoplastic films to increase the loft thereof.
2. Background and Relevant Art
Thermoplastic films are a common component in various commercial and consumer products. For example, grocery bags, trash bags, sacks, and packaging materials are products that are commonly made from thermoplastic films. Additionally, feminine hygiene products, baby diapers, adult incontinence products, and many other products include thermoplastic films to one extent or another.
The cost to produce products including thermoplastic film is directly related to the cost of the thermoplastic film. Recently the cost of thermoplastic materials has risen. In response, many manufacturers attempt to control manufacturing costs by decreasing the amount of thermoplastic material in a given product. One way manufacturers may attempt to reduce production costs is to use thinner films or stretch the thermoplastic films, thereby increasing surface area and reducing the amount of thermoplastic film needed to produce a product of a given size. These thin films can be manufactured by extruding thinner films or by cold formation stretching films after they are extruded. Unfortunately, stretched or otherwise produced thinner thermoplastic films can have undesirable properties. For example, thinner thermoplastic films can are typically more transparent or translucent and can have reduced physical properties. Additionally, consumers commonly associate thinner looking films with weakness. Such consumers may feel that they are receiving less value for their money when purchasing products with thinner films; and thus, may be dissuaded from purchasing thinner thermoplastic films. Accordingly, there is a need to create thinner films which have good physical properties and have the appearance of thicker, more expensive films.